Ok, so if you're using a hardware based HPF and starts at 40hz, and rolls off 6db per octave, then in theory it doesn't touch the 41hz samples. Correct?
Second, whenever I try and start my HPF (The delivered AU type HiPass) in Audacity at 40hz to see if I like the result better, it starts rolling off stuff at around 80 or 90hz, just a bit cause the frequency analysis turns up adjustments above 40 and 60hz.
So how do I simulate in audacity what would occur if I was using a piece of hardware (like the SD boxes)?